Back-to-back pcb usb connector

ABSTRACT

A double-sided USB connector may include a first PCB that may provide a first set of electrical contacts on its first side and solder pads on its second side. The first PCB may further include a components side, solder pads, and signal traces. The double-sided USB connector may also include a second PCB that may provide a second set of electrical contacts on its first side and terminals on its second side. Contacts selected from the second set of contacts may be connected to selected terminals, for example through via paths in the second PCB. Contacts from the first and second sets of contacts may selectively be connected to components on the first PCB using signal traces rather than wires. The first PCB may be joined to the second PCB by using the terminals, and the two PCBs may be packaged using a common molded body.

RELATED APPLICATIONS

The above-referenced patent application is a Divisional application ofU.S. patent Ser. No. 11/951,386, filed on Dec. 6, 2007, and also claimspriority under 37 U.S.C. §119(e) of U.S. Provisional Application No.60/868,939 filed on Dec. 7, 2006.

BACKGROUND

A portable electronic card, chip card, or integrated circuit(s) card(ICC), usually refers to various pocket-sized electronic cards withembedded integrated circuit(s), which can receive, process and outputdata. A pocket-sized electronic card typically has a molded body thatusually is made of plastic. Such cards include connectors, such as aUniversal Serial Bus (USB) connector, by which they interact withexternal devices or hosts. The use of electronic cards with USBconnector continues to become more prevalent.

One type of USB connectors includes a metal shell to protect theconnector's electrical contacts and to facilitate a better mechanicalgrip by USB ports. In some cases, though, a USB connector without ametal shell is preferred, for example because USB connectors without ametal shell are usually smaller and less expensive to manufacturerelative to shelled connectors. A type of USB connector which is gainingpopularity is the double-sided USB connector.

A double-sided USB connector consists of two, substantially opposing,contact areas, one of which provides a USB interface for datacommunications, and the other provides, or is used as, an electricalpower contact through which a USB host can power the embedded electroniccomponents of the USB card. In another type of electronic cards the“other” contact area is used to communicate another type of signal, forexample audio signal. The two substantially opposing contact areas ofthe double-sided connector typically are provided on the externalsurface of the USB card. Pocket-sided cards typically includedouble-sided USB connectors with exposed contact areas (i.e., noprotective shell is used to protect the electrical contacts) becausesuch cards, which typically have a thickness less than 2 millimeters(mm), cannot accommodate a shelled USB connector. “Wallet Flash”, apocket-sized card from Walletex Microelectronics Ltd, includes such aconnector.

Traditionally, pocket-sized cards include, as FIG. 1 illustrates, adouble-sided USB connector interfaced with a Printed Circuit Board (PCB)assembly that includes the card's embedded electronic components, whichare usually mounted on the PCB by using surface-mount technology (SMT).“SMT” references a method for constructing electronic circuits in whichthe components are mounted on the surface of a PCB by soldering thecomponents' terminals to corresponding solder pads on the PCB. “Solderpad” references flat, usually tin-lead, silver or gold plated copper padwithout a hole. SMT technology has largely superseded the through-holetechnology, a technology that involves fitting components with electricwire leads into holes in the circuit board. In surface-mountconstruction, the components are soldered to pads or lands on the outersurfaces of the PCB, for which reason surface mounting lends itself wellto a high degree of automation, reducing labor cost and greatlyincreasing production rates.

FIG. 1 schematically illustrates a pocket-sized card 100 in accordancewith the prior art. Pocket-sized card 100 includes two, traditionallyseparated, parts. The first part, generally designated as 101, includesa double-sided USB connector, the double-sided USB connector including afirst contact area 28 of the USB connector and a second contact area 30.Contact area 30 is consisted of a first set of electrical contacts andcontact area 28 is consisted of a second set of electrical contacts. Theelectrical contacts may be made from, or include, a flat, usuallytin-lead, silver or gold plated copper.

The second part of the pocket-sized card 100, generally designated as102, includes the PCB 24 section with electronic components 22 mountedthereon. Interconnecting (or interfacing) the double-sided USB connectorand (with) PCB 24 traditionally involves soldering electric wires 32both to the USB's contact areas 28 and 30 and to corresponding solderpads on PCB 24. As part of the assembly of PCB 24, terminals ofelectronic components 22 (the terminals generally designated as 26), aresoldered to corresponding solder pads on PCB 24. For the sake ofsimplicity, only three electrical components are shown mounted on PCB24. However, a typical card may have a different number of electroniccomponents, and usually more than three.

Traditionally, PCB 24 is first assembled and then connected to the USB'scontact areas 28 and 30 using electric wires 32. However, using wiressuch as wires 32 requires that a wire inventory be managed, and manualsoldering of wires is costly and time-consuming. In addition, manualwiring is prone to errors, for which reason a wiring inspection phasehas to be performed prior to the packaging of the card's components in amolded body, such as molded body 20 of card 100.

It would be beneficial to have a pocket-sized card which does notrequire hard-wiring the PCB to the USB connector and which wouldfacilitate the automation of its assembling process that may include,for example, a wave soldering technique. “Wave soldering” references asoldering process by which electronic components are soldered to a PCBto form an electronic assembly. As part of that process, electricalcomponents are placed on the PCB and the PCB is passed across a wave ofsolder such that the solder wets to the exposed solder pads of the PCB.U.S. Patent application 2007/0243769 ('769, for short), to Atsmon etal., discloses a double-sided USB connector with a main PCB, whichcarries the electrical components, and a connector PCB. However,according to '769 the connector PCB carries the two contact strips ofthe connector and whether the connector PCB can be soldered on top ofthe main PCB like the rest of its electrical components (i.e., in anautomated soldering process) is questionable. Therefore, it would alsobe desirable to have a method that would enable assembling portable andpocket-sized electronic cards with a better degree of automation. Itwould also be desirable to provide a USB card whose design reduces thenumber of costly assembly operations.

SUMMARY

The following embodiments and aspects thereof are described andillustrated in conjunction with systems, tools, and methods, which aremeant to be exemplary and illustrative but not limiting in scope.

As part of the present disclosure a double-sided universal serial bus(USB) connector, which may be a reversible connector, is disclosed, thedouble-sided USB connector may include a first PCB, which may have,support, include, or provide a first set of electrical contacts on itsfirst side and solder pads on its second side substantially opposite thefirst set of electrical contacts. The first PCB may further includecomponents on its components side, solder pads, and signal traces tocreate an electric circuitry.

The double-sided USB connector may also include a second PCB that mayhave, support, include, or provide, a second set of electrical contactson its first side and terminals on its second side (i.e., a terminalsside) which may be substantially opposite the second set of electricalcontacts. Contacts selected from the second set of contacts may beconnected to selected terminals, for example through via paths in thesecond PCB. The first PCB may be joined to the second PCB by using theterminals.

As part of the present disclosure a portable electronic card thatincludes the double-sided USB connector is also disclosed. Thedouble-sided USB connector may include a first set of electricalcontacts that form the USB connector's first contact area, and a secondset of electrical contacts that form the USB connector's second contactarea that is substantially opposite the first set of electricalcontacts.

The portable electronic card may further include a first PCB having acomponents side, on which one or more components are mounted, and afirst contact area formed by the first set of electrical contacts. Theportable electronic card may further include a second PCB having asecond contact area that is formed by the second set of electricalcontacts, and a terminals side on which terminals are provided. Contactsof the second set of electrical contacts may be selectively connected toterminals on the terminals side, and the first PCB may be joined to thesecond circuit board using the terminals on the terminals side of thesecond PCB.

Contacts selected from the first set of electrical contacts or from thesecond set of electrical contacts may be connected to selectedcomponents on the components side of the first PCB by using signaltraces rather than using wires. Connecting the selected contacts to theselected components may include connecting these contacts to selectedterminals in the bottom side (i.e., terminals side) of the second PCBand soldering the selected terminals to solder pads on the first PCB.The first PCB and the second PCB may be packaged in a common moldedbody. The portable electronic card may be a smart card or a portablestorage card.

As part of the present disclosure a method of assembling a portable cardhaving a double-sided USB connector is disclosed. The portable cardassembling method may include a) providing a first PCB with solder padsand signal traces, and with components mounted on a top side of thefirst PCB; b) providing a first set of electrical contacts to a bottomside of the first PCB to thereby form a first contact area of the USBconnector; c) providing a second PCB, the second PCB having terminals ona bottom side of the second PCB; d) providing to a top side of thesecond PCB a second set of electrical contacts to thereby form a secondcontact area of the reversible USB connector; and e) connecting contactsselected from said first or second set of contacts to selectedcomponents using the signal traces rather than using electrical wires.

In addition to the exemplary aspects and embodiments described above,further aspects and embodiments will become apparent by reference to thefigures and by study of the following detailed description.

BRIEF DESCRIPTION OF THE DRAWINGS

Exemplary embodiments are illustrated in referenced figures. It isintended that the embodiments disclosed herein are illustrative ratherthan restrictive. The disclosure, however, may better be understood withreference to the following detailed description when read with theaccompanying figures, in which:

FIG. 1 schematically illustrates an exemplary pocket-sized electroniccard according to related art;

FIG. 2 schematically illustrates an exemplary pocket-sized electroniccard in accordance with the present disclosure;

FIG. 3 schematically illustrates the upper side of the electronic cardof FIG. 2;

FIG. 4 shows a cross-sectional view of the electronic card of FIG. 3along line A-A; and

FIG. 5 is a method of assembling a portable electronic card inaccordance with an embodiment of the present disclosure.

It will be appreciated that for simplicity and clarity of illustration,elements shown in the figures are not necessarily drawn to scale.Further, where considered appropriate, reference numerals may berepeated among the figures to indicate like, corresponding or analogouselements.

DETAILED DESCRIPTION

The claims below will be better understood by referring to the presentdetailed description of embodiments of the invention. This descriptionis not intended to limit the scope of claims but instead to provideexamples of the invention.

In accordance with one embodiment, a novel double-sided USB connectorfor a pocket-sized electronic card is provided, which includes a firstPCB (interchangeably referred to herein as a “main PCB”) and a secondPCB (interchangeably referred to herein as a “via PCB”) mounted on themain PCB as an additional or supplemental component. A novel portablestorage card is also provided, which includes the novel double-sided USBconnector. The double-sided USB connector may be reversible.

By using a combination of a main PCB and a via PCB in the way disclosedherein, interconnection electric wires similar to wires 32 of FIG. 1 areavoided, and signal traces can beneficially be used instead. Inelectronics, “signal trace” of (i.e., on, and sometimes within) a PCB isthe equivalent of an electric wire for conducting electrical signals.Each signal trace typically is consisted of a flat, narrow part of thecopper foil that remains after etching, a process that results in theremoval of unused copper on the PCB. Signal traces are designed as partof the general layout design of the PCB. Depending on the general layoutdesign of a PCB, signal traces can include one or more via paths.

The main PCB of the present disclosure can be similar to PCB 24 of FIG.1, with the exception that the main PCB also accommodates for a firstset of electrical contacts of the novel connector on one of its sidesand a via PCB on its other side, which is the side of the main PCBreferred to herein as the “components side” of the main PCB. Due to therelatively small thickness of pocket-sized electronic cards, the mainPCB can carry components only on one side, though this approach maychange in the future.

The via PCB holds a second set of electrical contacts of the novelconnector on one of its sides, and it may provide, or may include, viapaths (hence referring to it as a “via PCB”) through which electricalcontacts selected from the second set of electrical contacts can beconnected to the main PCB using soldering pads. In PCB design, “viapath”, or more commonly “via”, references a pad with a plated hole thatinternally connects copper tracks from one layer of the PCB to otherlayer(s), or one side of the PCB to the other. The holes (i.e., viapaths) are either electroplated or small rivets may be inserted. As saidabove, a signal trace in a card may include one or more via paths. Themain PCB and the via PCB may be packaged in a common molded body torender mechanical endurance to the electronic card.

FIG. 2 schematically illustrates a portable electronic card, generallyshown at 200, in accordance with one embodiment. Portable card 200includes a double-sided USB connector, generally designated as 201.Double-sided connector 201 may be a reversible connector, a USBconnector, a reversible USB connector, or another type of connector.

Double-sided connector 201 may include a first printed circuit board(PCB) 40 that may have, support, or provide, a first set of electricalcontacts such as electrical contacts 42 on its first side (the bottomside of PCB 40), and solder pads (not shown in FIG. 2) on its secondside (i.e., the top side, or components side, of PCB 40). The solderpads may reside substantially opposite the first set of electricalcontacts 42. “Substantially opposite” refers to full, partial, or evenno, overlapping between electrical contacts of the first set ofelectrical contacts and the solder pads. For the sake of illustration,three exemplary components are shown mounted on PCB 40 using terminals44.

Double-sided connector 201 may also include a second PCB 38 that mayhave, support, or provide, a second set of electrical contacts 35 on itsfirst side (i.e., its top side) and terminals, generally shown at 46, onits second side (i.e., a bottom side, or terminals side, of PCB 38). Thesecond set of electrical contacts 35 may be substantially opposite theterminals 46. “Substantially opposite” may include full overlapping,partial overlapping, or even no overlapping, between electrical contactsof the second set of electrical contacts and terminal 46. As shown inFIG. 2, second PCB 38 generally resides in-between, or it is“sandwiched” between, the first set of electrical contacts 42 and thesecond set of electrical contacts 35 of double-sided connector 201. Thefirst set of electrical contacts 42 and the second set of electricalcontacts 35 may substantially be parallel and they may oppose oneanother, though this is not mandatory. Terminals 46 of second PCB 38 areadjacent the solder pads of PCB 40.

Contacts from the second set of electrical contacts 35 may selectivelybe connected to terminals 46, preferably through vias in the second PCB38. Second PCB 38 and its terminals 46 may be designed as an integralpart of the artwork of first PCB 40. This way, second PCB 38 can bemounted on first PCB 40 as an additional or supplemental component, forexample by soldering its terminals 46 to corresponding solder pads onthe first PCB 40.

Contacts selected from the first set or second set of electricalcontacts (42 and 35, respectively) may be connected to selectedcomponents on the components side of the first PCB 40 using signaltraces rather than using electric wires. By “first set or second set” ismeant from the first set of electrical contacts 42, or from the secondset of electrical contacts 35, or from both. In an embodiment of thepresent disclosure the portable electronic card is a portable storagecard that may include the double-sided connector disclosed herein. Thefirst set or second set of electrical contacts (42 and 35, respectively)may be recessed relative to the surface of the portable storage card.

Each of electrical contacts 42 and 35 may be made from, or include, aflat, usually tin-lead, silver or gold plated copper. The first set ofelectrical contacts 42 can be designed as part of the artwork of firstPCB 40. The second set of electrical contacts 35 can be designed as partof the artwork of second PCB 38.

A plurality of mechanical redundant terminals on the second PCB 38 maybe soldered to redundant solder pads on the first PCB 40. The pluralityof mechanical redundant terminals may be part of, or selected from,terminal 46, or they may be additional terminals in the terminals sideof second PCB 38. In other words, the terminals side of second PCB 38may include as many electrical terminals as required for the operationof portable electronic card 200, and, optionally, one or more redundantterminals. A terminal in the terminals side of second PCB 38 may beredundant only in the mechanical sense, in which case it will not bepart of the electrical circuitry. On the other hand, a terminal in theterminals side of second PCB 38 which is electrically redundant is alsoredundant mechanically.

The first PCB 40 may be joined to the second PCB 38, for example byusing terminals 46, for example by soldering terminals 46 to solder pads(not shown in FIG. 2), thereby making connector 201 “double-sided”. Asstated before, if both the first set of electrical contacts 42 and thesecond set of electrical contacts 35 have the same functionality (e.g.,they are both assigned, for example, USB functionality), thedouble-sided connector 201 is said to be “reversible”. Regarding thecoupling of a reversible connector to a port, in a first couplingorientation, the first set of electrical contacts 42 mechanicallytouches the port contacts and in a second coupling orientation thesecond set of electrical contacts 35 mechanically touches the portcontacts.

By using two printed circuit boards such as first PCB 40 and second PCB38, portable electronic cards can automatically be assembled using areflow soldering process. “Reflow soldering” references a common meansto attach a surface mounted component to a circuit board. In general,“reflow” involves applying solder paste, positioning the electroniccomponents, and reflowing the solder to melt the powder particles in thesolder paste, with the surfaces being joined together, and solidifyingthe solder to create a strong metallurgical bond. Typically,double-sided connector 201 is several times thicker than first PCB 40.Typically, second PCB 38 is also several times thicker than first PCB40. The methodology embodied in double-sided connector 201 can be usedwith, or applied to, various kinds of electronic cards.

FIG. 3 shows the top view of a typical portable electronic card, shownat 50, in accordance with one embodiment. Card 50 includes adouble-sided connector (generally shown at 301), the construction ofwhich is similar to the construction of double-sided connector 201 ofFIG. 2. Double-sided connector 301 may include a first PCB (not shown inFIG. 3) similar to first PCB 40 of FIG. 2, and a second PCB 302 (partlyshown in FIG. 3) similar to second PCB 302. Double-sided connector 301,which may be, for example, a reversible connector, a USB connector, or areversible USB connector, may include a first set of electrical contactsand a second set of electrical contacts 54, which reside on the (hidden)first PCB and on the second PCB 302, respectively, of card 50. Thesecond set of electrical contacts 54 are visible through an opening 52in the body 300 of card 50.

The external surface of second PCB 302 and the external surface of thefirst PCB (not shown in FIG. 3) are sufficiently recessed relative tothe surface of the card's body 300, as explicitly shown in FIG. 4, toprevent the connector's contacts from being short circuited by ametallic shell of a receptacle port (not shown), for example, whendouble-sided connector 301 engages a USB port. A method for protectingelectrical contacts from being short circuited is disclosed in U.S. Pat.No. 7,094,086.

FIG. 4 shows a cross-section A-A of the card 50 of FIG. 3 alongcross-section line 56. The connector's first set of electrical contacts54 is recessed relative to surface 401 of card 50, and second set ofelectrical contacts 66 is shown recessed relative to external surface402 of card 50. Slants edges 64 in the connector 301 facilitate smoothinsertion into and extraction of card 50 from a USB port, for example.

Referring to FIG. 57 it shows a flow chart of an electronic cardassembling method, according to the present disclosure. FIG. 5 will bedescribed in association with FIG. 2. At step 510 a first PCB 40 isprovided with solder pads (not shown in FIG. 2) and signal traces, andwith components mounted on a top side (also referred to herein as“components side”) of first PCB 40. At step 520 a first set ofelectrical contacts 42 is provided to a bottom side of first PCB 40 tothereby form, create, or provide, a first contact area of thedouble-sided connector 201. At step 530 a second PCB 38 is provided withterminals on its bottom side (also referred to herein as “terminalsside”). At step 540 a second set of electrical contacts 35 is providedto a top side of the second PCB 38 to thereby form, create, or provide,a second contact area of the USB connector 201. At step 550 contactsselected from the first or second set of contacts (42 or 35,respectively) are connected to selected components 36 using signaltraces rather than using electrical wires. Connecting selected contactsto selected components may include connecting these contacts to selectedterminals in the bottom side of the second PCB 38, and soldering theseterminals to selected solder pads on the first PCB 40. The method mayfurther include packaging the first PCB 40 and the second PCB 38 in acommon molded body. The portable card may be a smart card or a storagecard.

Regarding FIG. 5, different or additional steps may be carried out, andsteps may be joined together or be divided into sub-steps, and the orderof the steps may differ. For example, the second PCB 38 may be providedbefore the first PCB 40. Likewise, the first contract area may be formedon the first PCB 40 before mounting the components on first PCB 40, andthe second contact area may be formed on the second PCB 38 before thefirst contact area is formed on the first PCB 40.

Having thus described exemplary embodiments of the invention, it will beapparent to those skilled in the art that modifications of the disclosedembodiments will be within the scope of the invention. For example, theportable card's connector does not necessarily have to be a USBconnector or a reversible connector. In fact, principles taught by thepresent disclosure can likewise be applicable, mutatis mutandis, toother types of connectors, including to one-sided connectors.Accordingly, additional alternations, modifications, and improvements ofthe disclosed invention, though not expressly described above, arenonetheless intended and implied to be within spirit and scope of theinvention.

1. A double-sided universal serial bus connector comprising: a) a firstprinted circuit board having a first set of electrical contacts on itsfirst side and solder pads on its second side, the solder pads beingsubstantially opposite the first set of electrical contacts, and signaltraces; and b) a second printed circuit board having a second set ofelectrical contacts on its first side and terminals, substantiallyopposite the second set of electrical contacts, on its second side,contacts selected from the second set of contacts being connected toselected terminals, wherein said first printed circuit board is joinedto said second printed circuit board using said terminals, therebymaking the universal serial bus connector reversible.
 2. The universalserial bus connector according to claim 1, in which said first set ofelectrical contacts and said second set of electrical contacts aresubstantially opposed to each other.
 3. The universal serial busconnector according to claim 1, in which contacts selected from saidfirst or said second set of electrical contacts are connected to saidsignal traces.
 4. The universal serial bus connector according to claim1, in which said first PCB and said second printed circuit board arejoined by soldering said terminals to said solder pads.
 5. The universalserial bus connector according to claim 1, further comprising: c) aplurality of mechanical redundant terminals on said second printedcircuit board to be soldered to redundant solder pads on said firstprinted circuit board.
 6. The universal serial bus connector accordingto claim 5, in which a mechanical redundant terminal is alsoelectrically redundant.
 7. The universal serial bus connector accordingto claim 1, in which said first PCB and said second PCB are integrallypackaged in a common molded or encapsulating body.
 8. The universalserial bus connector according to claim 1, in which the universal serialbus connector is reversible.
 9. A portable electronic card that includesthe double-sided universal serial bus connector recited in claim
 1. 10.The portable electronic card according to claim 9, wherein the portableelectronic card is a smart card.
 11. The portable electronic cardaccording to claim 9, wherein the portable electronic card is a portablestorage card.
 12. The portable electronic card according to claim 9, inwhich the first and the second sets of electrical contacts are recessedrelative to the surface of the portable electronic card.
 13. A portablestorage card, comprising: a) a reversible universal serial bus connectorcomprising: a first set of electrical contacts; and a second set ofelectrical contacts substantially opposite said first set of electricalcontacts; b) a main printed circuit board having a components side onwhich one or more components are mounted, and a contact side on whichsaid first set of electrical contacts is provided; and c) a via printedcircuit board having a contact side on which said second set ofelectrical contacts is provided, and a terminals side on which terminalsare provided, wherein contacts of said second set of electrical contactsare selectively connected to terminals on said terminals side, andwherein said main printed circuit board is joined to said via circuitboard using said terminals.
 14. The portable storage card according toclaim 13, wherein contacts selected from said first electrical contactor said second set of electrical contacts are connected to selectedcomponents on said components side using signal traces rather than usingwires.
 15. The storage card according to claim 13, wherein said mainprinted circuit board and said via printed circuit board are packaged ina common molded body.